Nuclear Magnetic Resonance (NMR) spectrometers have been in use for many years and can be used to provide imaging and/or analysis of a sample being tested. In general, a typical single channel NMR spectrometer is comprised of three main components: a pulse sequencer, an NMR transmitter, and an NMR receiver. The NMR transmitter and the NMR receiver both interface to an external antenna (i.e., coil) that is typically part of an NMR probe that receives the sample. An external magnet can also be provided to provide a static magnetic field (typically referred to as the B0 field) to the sample during NMR experiments. The pulse sequencer and the NMR transmitter cooperate to supply a train of pulses of an oscillating RF (radiofrequency) signal to the external antenna in order to excite macroscopic nuclear spins in the sample. The NMR receiver receives NMR signals detected by the external antenna and amplifies the received NMR signals with low noise and high gain. The NMR signals produced by the NMR receiver are processed by signal processing circuitry (typically involving digitization by an analog-to-digital converter and data processing by a data processor) in order to derive useful physical and chemical information.
NMR logging is an established type of NMR measurement wherein an NMR spectrometer is lowered into a borehole in the earth, and NMR measurements are performed to determine properties within and/or surrounding the borehole. However, existing NMR logging spectrometers have a number of drawbacks, including high expense and support for a limited pulse sequence format for the NMR experiments. Furthermore, the downhole sensor package designed to fit within the borehole can be large in size and very heavy.